Tuesday, November 18, 2008

AI pushbacks

Something I've wanted to see in games for a long time is dynamic enemy AI with enough sophistication to shape a gameworld without overly frustrating players.

If AI characters each have a variety of goals and a variety of behaviors for achieving those goals, then gameplay can continually surprise and each player can have unique experiences to share. But even when games include such variety, they rarely enable AI to regain what the player has fought for. Player progress is rarely tentative.

In Saints Row and Saints Row 2, players seek to conquer the city neighborhood-by-neighborhood. After taking a neighborhood, there's usually a pushback. Whatever gang used to own that neighborhood tries to take it back. But no dynamics are involved in the event. Enemy AI don't move into the neighborhood while the player is away, but simply appear there instantaneously. Because it's a completely scripted event, there are no surprises in the fight to take back that territory. A fixed number of gang leaders of fixed strength and effect appear in fixed locations, which the player must kill to secure a zone with fixed borders. Judging from experience, each territory can only have one pushback.

LOTR: Battle for Middle Earth 2 involves more genuine pushbacks, in its War of the Ring mode. The setting is war, and wars can be lost. This is unlike a typical adventure game, in which it's assumed the player will win the war and only battles can be lost. In War of the Ring (similar to the boardgame Risk), strategic AI decisions are fairly predictable, but territory geography and limited resources combine to make simultaneous offense and defense difficult. To be strong enough to seize new territories, the player must sometimes leave old territories vulnerable to attack. Also, each territory awards particular benefits for ownership. These dynamics supplement relatively static AI to result in dynamic pushbacks. The player's ability to predict the place, time, and manner of pushbacks is limited. A pushback in a particular territory can be repeated multiple times, and the enemy's invasions can be devastating.

Now, The Godfather 2 gets its turn: "The Godfather 2 is dynamic and reactive, families react with complex "countermoves" based on the players actions and leveraging very human behaviors like revenge and coercion." Though the game includes a strategic map, The Don's View (shown above), "revenge and coercion" sound like ground-level interactions. I'm anxious to see how this turns out.